The present invention relates to apparatus for connecting load bearing structural members and more especially, but not exclusively, to apparatus for connecting beams, columns and other like structural members. The invention also relates to a method of connecting such members.
Conventional steel support structures or frameworks are fabricated from preformed beams, columns and like structural members. Typically, beams carry welded brackets which are aligned with preformed holes formed in columns, the beams and columns then being joined by bolts or like connecting devices. Similarly, for connecting secondary beams to primary beams, steel brackets welded to the webs of the secondary beams are aligned with holes preformed in the webs of primary beams (or vice versa), the beams then being connected by through bolts or the like. The provision of these brackets and holes adds cost to the manufacturing process and the subsequent on-site alignment and securement can be time consuming and expensive.
It is known to provide modular supporting structures wherein upright structural members are provided with one or more slots which receive projections of horizontal structural members. Such supporting structures are disclosed in, inter alia, U.S. Pat. No. 5,592,789, Patent Applications GB-A-1051557 and GB-A-1240774. A framework assembly is known from U.S. Pat. No. 3,513,606 in which right angled brackets are mounted to a vertical frame member by virtue of a slotted adaptor bracket secured to the frame member by a spring loaded nut and bolt assembly.
Such structures and assemblies suffer from a number of disadvantages.
U.S. Pat. No. 3,977,801 discloses a device for laterally interconnecting structural members such as beams and columns. The device comprises a plate with a face and a circumscribing edge, at least one slot extending inwardly from one edge of the plate and at least one stud extending outwardly from the face of the plate. The plate is fixed vertically by welding to an end of a beam whereby the stud or studs extend into open-ended slots formed in the opposed end of the column (or a second plate portion welded to one face of the column) with suitably positioned studs extending outwardly from the opposed face of the column (or separate plate portion) extending into the open-sided slots of the plate.
Use of such a device involves a significant amount of welding to achieve the required column to beam or beam to beam connections, this being both costly and time consuming.
It is an object of the present invention to provide apparatus for and a method of connecting columns, beams and like structural members which avoids, or at least alleviates, structural and other disadvantages inherent in support members formed with connection slots as discussed previously, and which can be assembled and dismantled with relative ease.
In one aspect, the invention provides a connector for providing a load supporting connection between first and second structural members, the connector comprising a flange for connection to one of the two structural members and a web which subtends an angle to the flange and is formed with at least one slot bordered on all sides by web material and includes a head and a neck coextensive with the head.
The flange may be formed with a series of slots each of which includes a head and a neck coextensive with the head. In a preferred embodiment, the width of the neck is less than that of the head.
According to the present invention in another aspect, there is provided a connector for providing a load supporting connection between a first structural member (the xe2x80x9csupporting memberxe2x80x9d) and a second structural member supported thereby (the xe2x80x9csupported memberxe2x80x9d), the connector comprising a flange and an integral web formed with an array of two or more spaced slots, each having an upper portion dimensioned to receive a head of a stud which projects from a surface of the supported member and a coextensive lower portion dimensioned to receive the shank of the stud, the width of each shank receiving slot portion being less than the width of the respective stud head.
The flange of the connector may also be formed with an array of two or more spaced slots each dimensioned to receive a head of a stud which projects from a surface of the supporting member and a coextensive upper portion dimensioned to receive the shank of the stud.
Preferably, each array comprises two or more generally vertically spaced slots.
According to the present invention in a further aspect, there is provided an assembly of a connector and first and second structural members, the connector providing a connection between the structural members and comprising a flange and a web formed with an array of two or more spaced slots each having an enlarged upper portion and a coextensive narrower lower portion, the enlarged portions of each slot being dimensioned to receive a head of a stud which projects from the surface of a first structural member to be connected and the narrower portion of each slot being dimensioned to receive the shank of one such stud and to trap the head of that stud behind the margins of the slot narrower portions thereby to connect the structural members together.
The flange may also be formed with an array of two or more spaced slots each having an enlarged lower portion and a coextensive narrower upper portion.
Preferably, each array comprises two or more generally vertically spaced slots.
In a still further aspect, the invention provides an assembly comprising first and second structural members and a connector providing a load supporting connection between the first structural member and the second structural member to be supported thereby, each such member having projecting from at least one surface a series of studs each having a shank secured to the respective structural member and a head, the connector comprising a flange and a web which subtends an angle to the flange, a series of slots formed in the web each comprising at least two generally vertically spaced slots each of which includes a head and a coextensive neck, each slot being dimensioned to allow the head of a stud to pass therethrough and each slot neck being dimensioned to receive the shank of a stud.
In a yet further aspect, the invention provides a connector for providing a load supporting connection between first and second structural members, the connector comprising a flange formed with a series of slots and a web which subtends an angle to the flange and is also formed with a series of slots, each such series comprising at least two slots one above the other, and each slot including a head and a narrower neck coextensive with the head, each slot of the flange being positioned with its head below its neck and each slot of the web being positioned with its head above its neck.
The term xe2x80x9cstudxe2x80x9d as used herein refers to a member which projects from or through a surface of a beam, column or like structural member and comprises a head located at one end of a shank.
The term xe2x80x9cgenerally verticalxe2x80x9d as used herein with reference to the slots of an array or series means that one such slot is positioned above another slot or slots of the array or series. The term embraces situations in which one slot is positioned above but to one side of another slot or slots.
Preferably, the studs project horizontally, or substantially horizontally, from each structural member.
The shanks of the studs are typically secured to the respective structural member by welding. Alternatively, the shank may pass through a suitably dimensioned hole formed in the respective structural member, the shank being secured in place by a bolt screwed onto a threaded end of the shank. In this arrangement, the shank may include a collar whose end abuts the margin around the hole formed in the member and acts to space the stud head from the member. Other securement means maybe provided. Preferably the studs are shear studs and are formed of steel, for example plain carbon steel or galvanised steel.
Shear studs are preferably evenly spaced, along all or part of the length and/or width of the respective structural member. Typically the studs will be aligned substantially vertically or horizontally along all or part of the span of the structural member. The studs may be of equal length.
The length of each stud shank is generally dependant upon the physical properties of the connector and/or the plate from which the connector is produced. Preferably, the length of each stud shank is only marginally greater than the wall thickness of the connector. Typically, the shank length is up to several millimeters greater than the thickness of the plate from which the slot is cut, for example up to 5 mm greater, preferably between 1 and 3 mm. Typically, the length of each stud shank will be between 6 and 26 mm, the respective plate thickness being between 5 and 25 mm. A typical plate thickness is between 10 and 20 mm.
The shank diameter is generally dependent on the load to be supported by the connector. Typically, the shank diameter is between 5 and 50 mm, preferably between 10 and 30 mm, for example 19 mm.
In a preferred embodiment, the slots are keyhole shaped. By the term xe2x80x9ckeyholexe2x80x9d is meant a slot having a necked portion which is coextensive with an enlarged head portion. The margins of the head and necked portions of the slots may be curvilinear. The head portion of the slot is sufficiently large to receive the head of a stud. Typically, the diameter of the enlarged head portion of the slot is between 0.5 and 3 mm larger than the diameter or width of the stud head.
The necked portion of the slot is typically shaped to engage with (or be marginally spaced from) the sides of the shank of the stud. Typically the width of the necked portion of the slot is between 0.5 and 3 mm larger than the stud shank diameter.
The shapes of the slots and the cross sections of the stud heads and shanks are preferably circular, although other shapes may be adopted. Thus, the stud head and the enlarged portion of the slot may, for example, be round, square, triangular shaped or any other appropriate shape.
The structural members are generally profiled sections of cold-rolled or hot-rolled steel and typically comprise xe2x80x9cHxe2x80x9d section columns and xe2x80x9cIxe2x80x9d section beams. Preferably, the structural members are hot rolled columns and beams.
Preferably, the beams, columns, structural members and connectors are produced from steel. Other materials having the required physical properties may however be employed.
The connector may comprise an angle plate comprising a flange and an integral web set generally normal to one another. Preferably, the connector comprises an angle plate of xe2x80x9cLxe2x80x9d or xe2x80x9cTxe2x80x9d section. Alternative connector sections may, however, be employed. The angle between the flanges is typically between 60xc2x0 and 120xc2x0; preferably the angle is 90xc2x0.
The connector may be formed from lengths of hot or cold-rolled steel, typically of I-section. T-sectioned connectors may be formed by splitting I-sectioned or H-sectioned profiled lengths of rolled steel. In a preferred form, the connectors are produced from lengths of hot-rolled steel. Alternatively, the connectors may be formed from steel strip with stamped-out slots and then folded by cold forming to produce an xe2x80x9cLxe2x80x9d section.
Alternatively, the connector may be produced from steel plates in which the required slots are formed, for example by flame cutting or a stamping process, the plates then being welded together to produce the required xe2x80x9cTxe2x80x9d or xe2x80x9cLxe2x80x9d section.
In one embodiment the connector comprises a metal angle plate including a flange and an integral web each formed with an array of generally vertically spaced keyhole-shaped slots, the slots of the flange being inverted relative to the slots of the web.
In this embodiment, the keyhole slots of the flange each have an enlarged lower head portion for receiving the head of a shear stud and a coextensive narrower upper neck portion for engaging the shank of the shear stud to effect a first connection between the connector and a supporting column or primary beam whereby the connector, sensu lato, is supported by the supporting column or primary beam. The connector, sensu stricto, xe2x80x9changs fromxe2x80x9d the studs of the supporting column or primary beam.
The slots of the web effect a second connection between the connector and a beam supported by the supporting column or primary beam whereby the connector, sensu lato, supports the supported beam. Essentially the connector, sensu stricto, provides a xe2x80x9changerxe2x80x9d which supports the supported or secondary beam.
The slots may be formed in the connector by flame cutting, stamping or other suitable process.
In another embodiment, the connector comprises a metal angle plate including a flange and an integral web, the web only being formed with an array of generally vertically spaced key-hole slots. In this embodiment, the flange is secured to the supporting member by bolts, welding or the like with the slots of the web effecting a second connection between the connector or a supported member.
In another aspect, the invention provides an assembly of a first structural member (the xe2x80x9csupporting memberxe2x80x9d), a second structural member supported thereby (the xe2x80x9csupported memberxe2x80x9d) and a connector for providing a load bearing connection between the two structural members, a plurality of studs projecting from at least one surface of the supported member, each stud including a shank secured to the supported member and a head, the connector comprising a flange and a web formed with a series of generally vertically spaced slots each of which includes a head and a restricted neck positioned below and coextensive with the head, the slots being dimensioned and sited to enable the heads of studs which project from the surface of the supported member to pass through the heads of the slots of the connector web with the stud shanks being received within the necks of the slots, the arrangement being such that on assembly the rear face of the flange makes contact with or lies adjacent to an abutting face of the supporting member and the rear face of the web lies adjacent to or makes contact with an abutting face of the supported member.
The flange may be bolted, welded or otherwise secured to the supporting member.
Alternatively, a plurality of studs may also project from at least one surface of the supporting member, each stud including a shank secured to the supporting member and a head; in this embodiment, a series of generally vertically spaced slots are formed in the flange, each such slot including a head and a restricted neck positioned above and coextensive with the head, the slots being dimensioned and sited to enable the heads of the studs which project from the surface of the supporting member to pass through the heads of the slots of the connector flange with the stud shanks being received within the necks of the slots.
In a yet further aspect, the invention provides a method of providing a load bearing connection between a first structural member and a second structural member supported thereby, the method comprising the steps of securing to at least one face of each structural member a plurality of studs each having a shank and a head, supporting on the studs of the first structural member a connector which includes a flange formed with a plurality of slots each having a head and a coextensive neck positioned above the head, the heads of the studs of the first member passing through the slot heads of the flange with the stud shanks being received within the flange slot necks, the connector also including a web formed with a plurality of slots each having a head and a coextensive neck positioned below the head, the heads of studs of the second structural member passing through the slot heads of the web with the stud shanks being received within the slot necks.